The bl_curve code has some room for improvement.
...
<6>Monitor sense value = 0x60b
<6>using video mode 13 and color mode 0.
<4>Console: switching to colour frame buffer device 104x39
<6>fb0: valkyrie frame buffer device
...
inst-sys:~ # cat /proc/fb
0 valkyrie
inst-sys:~ # l /sys/class/graphics/fb0/
total 0
drwxr-xr-x 2 root root 0 Sep 21 11:54 ./
drwxr-xr-x 4 root root 0 Sep 21 11:53 ../
-rw-r--r-- 1 root root 4096 Sep 21 12:15 bits_per_pixel
-rw-r--r-- 1 root root 4096 Sep 21 12:15 bl_curve
-rw-r--r-- 1 root root 4096 Sep 21 12:15 blank
-rw-r--r-- 1 root root 4096 Sep 21 12:15 console
-rw-r--r-- 1 root root 4096 Sep 21 12:15 cursor
-r--r--r-- 1 root root 4096 Sep 21 12:15 dev
-rw-r--r-- 1 root root 4096 Sep 21 12:15 mode
-rw-r--r-- 1 root root 4096 Sep 21 12:15 modes
-r--r--r-- 1 root root 4096 Sep 21 12:15 name
-rw-r--r-- 1 root root 4096 Sep 21 12:15 pan
-rw-r--r-- 1 root root 4096 Sep 21 12:15 rotate
-rw-r--r-- 1 root root 4096 Sep 21 12:15 state
-r--r--r-- 1 root root 4096 Sep 21 12:15 stride
lrwxrwxrwx 1 root root 0 Sep 21 12:15 subsystem -> ../../../class/graphics/
--w------- 1 root root 4096 Sep 21 12:15 uevent
-rw-r--r-- 1 root root 4096 Sep 21 12:15 virtual_size
inst-sys:~ # head /sys/class/graphics/fb0/*
==> /sys/class/graphics/fb0/bits_per_pixel <==
8
==> /sys/class/graphics/fb0/bl_curve <==
Segmentation fault
inst-sys:~ # dmesg
valkyriefb: vmode 13 does not support cmode 1.
Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc02c7bd8
Oops: Kernel access of bad area, sig: 11 [#1]
Modules linked in: tulip mesh cpufreq_ondemand loop nfs nfs_acl lockd sunrpc sg st sd_mod sr_mod scsi_mod ide_cd cdrom
NIP: C02C7BD8 LR: C0170EBC CTR: C0170E90
REGS: c4209db0 TRAP: 0300 Not tainted (2.6.18-rc7-git1-2-default)
MSR: 00009032 <EE,ME,IR,DR> CR: 28042488 XER: 00000000
DAR: 00000000, DSISR: 22000000
TASK = c7fc8190[2853] 'head' THREAD: c4208000
GPR00: C4209E6C C4209E60 C7FC8190 C0B77614 C41D5000 C41D5000 00000000 00008000
GPR08: 00000000 C0B77618 00000000 00000000 00000000 100200C8 10020000 00000001
GPR16: 10006D08 7FDF9B3C 100A0000 10080000 00000003 7FDF9CAB C4209F20 C2FCDC78
GPR24: C038BC14 C01EF568 7FDF7858 C41D5000 C0B77614 C0B77400 C7FC8190 C0B77614
NIP [C02C7BD8] __mutex_lock_slowpath+0x2c/0xa4
LR [C0170EBC] show_bl_curve+0x2c/0xa0
Call Trace:
[C4209E60] [C02C7A54] mutex_lock+0x18/0x5c (unreliable)
[C4209E80] [C0170EBC] show_bl_curve+0x2c/0xa0
[C4209EB0] [C01EF594] class_device_attr_show+0x2c/0x44
[C4209EC0] [C00CC3BC] sysfs_read_file+0xb8/0x204
[C4209EF0] [C0083FE4] vfs_read+0xec/0x1c8
[C4209F10] [C0084444] sys_read+0x4c/0x8c
[C4209F40] [C00125F8] ret_from_syscall+0x0/0x40
--- Exception: c01 at 0xff589f8
LR = 0x100045e0
Instruction dump:
4e800020 9421ffe0 7c0802a6 39230004 bfc10018 7c7f1b78 7c5e1378 90010024
3801000c 9121000c 81690004 90090004 <900b0000> 91610010 90410014 3800ffff
On Thu, 21 Sep 2006 14:19:52 +0200
Olaf Hering <[email protected]> wrote:
> The bl_curve code has some room for improvement.
>
> ...
> <6>Monitor sense value = 0x60b
> <6>using video mode 13 and color mode 0.
> <4>Console: switching to colour frame buffer device 104x39
> <6>fb0: valkyrie frame buffer device
> ...
>
> inst-sys:~ # cat /proc/fb
> 0 valkyrie
> inst-sys:~ # l /sys/class/graphics/fb0/
> total 0
> drwxr-xr-x 2 root root 0 Sep 21 11:54 ./
> drwxr-xr-x 4 root root 0 Sep 21 11:53 ../
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 bits_per_pixel
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 bl_curve
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 blank
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 console
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 cursor
> -r--r--r-- 1 root root 4096 Sep 21 12:15 dev
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 mode
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 modes
> -r--r--r-- 1 root root 4096 Sep 21 12:15 name
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 pan
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 rotate
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 state
> -r--r--r-- 1 root root 4096 Sep 21 12:15 stride
> lrwxrwxrwx 1 root root 0 Sep 21 12:15 subsystem -> ../../../class/graphics/
> --w------- 1 root root 4096 Sep 21 12:15 uevent
> -rw-r--r-- 1 root root 4096 Sep 21 12:15 virtual_size
> inst-sys:~ # head /sys/class/graphics/fb0/*
> ==> /sys/class/graphics/fb0/bits_per_pixel <==
> 8
>
> ==> /sys/class/graphics/fb0/bl_curve <==
> Segmentation fault
> inst-sys:~ # dmesg
> valkyriefb: vmode 13 does not support cmode 1.
> Unable to handle kernel paging request for data at address 0x00000000
> Faulting instruction address: 0xc02c7bd8
> Oops: Kernel access of bad area, sig: 11 [#1]
>
> Modules linked in: tulip mesh cpufreq_ondemand loop nfs nfs_acl lockd sunrpc sg st sd_mod sr_mod scsi_mod ide_cd cdrom
> NIP: C02C7BD8 LR: C0170EBC CTR: C0170E90
> REGS: c4209db0 TRAP: 0300 Not tainted (2.6.18-rc7-git1-2-default)
> MSR: 00009032 <EE,ME,IR,DR> CR: 28042488 XER: 00000000
> DAR: 00000000, DSISR: 22000000
> TASK = c7fc8190[2853] 'head' THREAD: c4208000
> GPR00: C4209E6C C4209E60 C7FC8190 C0B77614 C41D5000 C41D5000 00000000 00008000
> GPR08: 00000000 C0B77618 00000000 00000000 00000000 100200C8 10020000 00000001
> GPR16: 10006D08 7FDF9B3C 100A0000 10080000 00000003 7FDF9CAB C4209F20 C2FCDC78
> GPR24: C038BC14 C01EF568 7FDF7858 C41D5000 C0B77614 C0B77400 C7FC8190 C0B77614
> NIP [C02C7BD8] __mutex_lock_slowpath+0x2c/0xa4
> LR [C0170EBC] show_bl_curve+0x2c/0xa0
> Call Trace:
> [C4209E60] [C02C7A54] mutex_lock+0x18/0x5c (unreliable)
> [C4209E80] [C0170EBC] show_bl_curve+0x2c/0xa0
> [C4209EB0] [C01EF594] class_device_attr_show+0x2c/0x44
> [C4209EC0] [C00CC3BC] sysfs_read_file+0xb8/0x204
> [C4209EF0] [C0083FE4] vfs_read+0xec/0x1c8
> [C4209F10] [C0084444] sys_read+0x4c/0x8c
> [C4209F40] [C00125F8] ret_from_syscall+0x0/0x40
> --- Exception: c01 at 0xff589f8
> LR = 0x100045e0
> Instruction dump:
> 4e800020 9421ffe0 7c0802a6 39230004 bfc10018 7c7f1b78 7c5e1378 90010024
> 3801000c 9121000c 81690004 90090004 <900b0000> 91610010 90410014 3800ffff
>
cc's added.
On Thu, Sep 21, 2006 at 12:37:42PM -0700, Andrew Morton wrote:
> On Thu, 21 Sep 2006 14:19:52 +0200
> Olaf Hering <[email protected]> wrote:
> > The bl_curve code has some room for improvement.
Agreed.
> > inst-sys:~ # dmesg
> > valkyriefb: vmode 13 does not support cmode 1.
> > Unable to handle kernel paging request for data at address 0x00000000
> > Faulting instruction address: 0xc02c7bd8
Seems like not all drivers use the framebuffer_alloc() function and
won't have an initialized mutex. But those don't have a backlight,
anyway.
What about the patch below? Does it work for you?
Signed-off-by: Michael Hanselmann <[email protected]>
---
diff -Nrup --exclude-from linux-exclude-from linux-2.6.18.orig/drivers/video/fbsysfs.c linux-2.6.18/drivers/video/fbsysfs.c
--- linux-2.6.18.orig/drivers/video/fbsysfs.c 2006-09-21 23:40:06.000000000 +0200
+++ linux-2.6.18/drivers/video/fbsysfs.c 2006-09-21 23:50:00.000000000 +0200
@@ -397,6 +397,12 @@ static ssize_t store_bl_curve(struct cla
u8 tmp_curve[FB_BACKLIGHT_LEVELS];
unsigned int i;
+ /* Some drivers don't use framebuffer_alloc(), but those also
+ * don't have backlights.
+ */
+ if (!fb_info || !fb_info->bl_dev)
+ return -ENODEV;
+
if (count != (FB_BACKLIGHT_LEVELS / 8 * 24))
return -EINVAL;
@@ -430,6 +436,12 @@ static ssize_t show_bl_curve(struct clas
ssize_t len = 0;
unsigned int i;
+ /* Some drivers don't use framebuffer_alloc(), but those also
+ * don't have backlights.
+ */
+ if (!fb_info || !fb_info->bl_dev)
+ return -ENODEV;
+
mutex_lock(&fb_info->bl_mutex);
for (i = 0; i < FB_BACKLIGHT_LEVELS; i += 8)
len += snprintf(&buf[len], PAGE_SIZE,
On Thu, Sep 21, Michael Hanselmann wrote:
> What about the patch below? Does it work for you?
Appears to work.
tangerine:~ # head /sys/class/graphics/fb0/*
==> /sys/class/graphics/fb0/bits_per_pixel <==
8
==> /sys/class/graphics/fb0/bl_curve <==
head: error reading `/sys/class/graphics/fb0/bl_curve': No such device
==> /sys/class/graphics/fb0/blank <==
==> /sys/class/graphics/fb0/console <==
==> /sys/class/graphics/fb0/cursor <==
==> /sys/class/graphics/fb0/dev <==
29:0
==> /sys/class/graphics/fb0/mode <==
==> /sys/class/graphics/fb0/modes <==
U:832x624p-74
==> /sys/class/graphics/fb0/name <==
valkyrie
==> /sys/class/graphics/fb0/pan <==
0,0
==> /sys/class/graphics/fb0/rotate <==
0
==> /sys/class/graphics/fb0/state <==
0
==> /sys/class/graphics/fb0/stride <==
832
==> /sys/class/graphics/fb0/subsystem <==
head: error reading `/sys/class/graphics/fb0/subsystem': Is a directory
head: cannot open `/sys/class/graphics/fb0/uevent' for reading: Permission denied
==> /sys/class/graphics/fb0/virtual_size <==
832,624
On Fri, 22 Sep 2006 13:26:22 +0200
Olaf Hering <[email protected]> wrote:
> On Thu, Sep 21, Michael Hanselmann wrote:
>
> > What about the patch below? Does it work for you?
>
> Appears to work.
>
> tangerine:~ # head /sys/class/graphics/fb0/*
> ==> /sys/class/graphics/fb0/bits_per_pixel <==
> 8
>
> ==> /sys/class/graphics/fb0/bl_curve <==
> head: error reading `/sys/class/graphics/fb0/bl_curve': No such device
>
> ==> /sys/class/graphics/fb0/blank <==
>
> ==> /sys/class/graphics/fb0/console <==
>
> ==> /sys/class/graphics/fb0/cursor <==
>
> ==> /sys/class/graphics/fb0/dev <==
> 29:0
>
> ==> /sys/class/graphics/fb0/mode <==
>
> ==> /sys/class/graphics/fb0/modes <==
> U:832x624p-74
>
> ==> /sys/class/graphics/fb0/name <==
> valkyrie
>
> ==> /sys/class/graphics/fb0/pan <==
> 0,0
>
> ==> /sys/class/graphics/fb0/rotate <==
> 0
>
> ==> /sys/class/graphics/fb0/state <==
> 0
>
> ==> /sys/class/graphics/fb0/stride <==
> 832
>
> ==> /sys/class/graphics/fb0/subsystem <==
> head: error reading `/sys/class/graphics/fb0/subsystem': Is a directory
> head: cannot open `/sys/class/graphics/fb0/uevent' for reading: Permission denied
>
> ==> /sys/class/graphics/fb0/virtual_size <==
> 832,624
Still looks like a bit of a mess, but I assume that's expected.
Michael, I take it that patch was final?
On Fri, Sep 22, 2006 at 04:02:55PM -0700, Andrew Morton wrote:
> Still looks like a bit of a mess, but I assume that's expected.
> Michael, I take it that patch was final?
For now, yes. Thanks for adding it to -mm.